/*      $NetBSD: doscommain.c,v 1.1 2024/06/29 13:45:14 rin Exp $       */

/*
* Copyright (c) 1996
*      Matthias Drochner.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/

/* argument line processing for DOS .COM programs */

#include <lib/libsa/stand.h>

/* The Program Segment Prefix */

static struct psp{
       char mist1[0x2c];
       short envseg;
       char mist2[0x80-2-0x2c];
       char cmdlen;
       char cmd[127];
} *PSP = (struct psp*)0;

static char* argv[64]; /* theor max */

static int whitespace(char);

static int
whitespace(char c)
{
       if ((c == '\0') || (c == ' ') || (c == '\t')
           || (c == '\r') || (c == '\n'))
               return (1);
       return 0;
}

enum state {skipping, doing_arg, doing_long_arg};

/* build argv/argc, start real main() */
int doscommain(void);
extern int main(int, char**);

int
doscommain(void)
{
       int argc, i;
       enum state s;

       argv[0] = "???"; /* we don't know */
       argc = 1;
       s = skipping;

       for (i = 0; i < PSP->cmdlen; i++){

               if (whitespace(PSP->cmd[i])) {
                       if (s == doing_arg) {
                               /* end of argument word */
                               PSP->cmd[i] = '\0';
                               s = skipping;
                       }
                       continue;
               }

               if (PSP->cmd[i] == '"') {
                       /* start or end long arg
                        * (end only if next char is whitespace)
                        *  XXX but '" ' cannot be in argument
                        */
                       switch (s) {
                       case skipping:
                               /* next char begins new argument word */
                               argv[argc++] = &PSP->cmd[i + 1];
                               s = doing_long_arg;
                               break;
                       case doing_long_arg:
                               if (whitespace(PSP->cmd[i + 1])) {
                                       PSP->cmd[i] = '\0';
                                       s = skipping;
                               }
                       case doing_arg:
                               /* ignore in the middle of arguments */
                       default:
                               break;
                       }
                       continue;
               }

               /* all other characters */
               if (s == skipping) {
                       /* begin new argument word */
                       argv[argc++] = &PSP->cmd[i];
                       s = doing_arg;
               }
       }
       if (s != skipping)
               PSP->cmd[i] = '\0'; /* to be sure */

       /* start real main() */
       return main(argc, argv);
}